Hydrogen Peroxide Production by Mycoplasma bovis and Mycoplasma agalactiae and Effect of In Vitro Passage on a Mycoplasma bovis Strain Producing High Levels of H₂O₂

Abstract

Hydrogen peroxide (H₂O₂) production and oxygen uptake during the oxidation of NADH and L-α-glycerophosphate (GP) by lysed cells was determined for the type and field strains ofMycoplasma bovis andM. agalactiae. NADH oxidation by all the strains showed variable production of H₂O₂ ranging from 0 to 1.21 mol/mol O₂ taken up. All strains were unable to oxidize GP, showing absence of GP oxidase activity. Some strains were identified that produced relatively high levels of H₂O₂ (>1.0 mol/mol O₂ taken up).In vitro passage ofM. bovis strain 119B96 showed reduced H₂O₂ production: 0.52, 0.16, and 0.07 mol/mol O₂ taken up after the 50th, 100th and 200th passages, respectively. SDS-PAGE analysis showed the loss of a protein band of 32 kDa after 50 passages. These preliminary studies show that not only does H₂O₂ production by potentially pathogenicMycoplasma spp. vary in the field but also that similar alterations can be induced by passage in culture. In the latter case, at least in oneM. bovis strain, this alteration has been shown by SDS-PAGE to be associated with a loss of specific protein production. Further study of these phenomena is essential background for the production of more efficient vaccines for mycoplasmas.